3 * Copyright (c) 2007 Konstantin Shishkov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavcodec/get_bits.h"
23 #include "libavcodec/unary.h"
27 #include "avio_internal.h"
30 #define MKMPCTAG(a, b) (a | (b << 8))
32 #define TAG_MPCK MKTAG('M','P','C','K')
36 TAG_STREAMHDR = MKMPCTAG('S','H'),
37 TAG_STREAMEND = MKMPCTAG('S','E'),
39 TAG_AUDIOPACKET = MKMPCTAG('A','P'),
41 TAG_SEEKTBLOFF = MKMPCTAG('S','O'),
42 TAG_SEEKTABLE = MKMPCTAG('S','T'),
44 TAG_REPLAYGAIN = MKMPCTAG('R','G'),
45 TAG_ENCINFO = MKMPCTAG('E','I'),
48 static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
57 static inline int64_t bs_get_v(uint8_t **bs)
75 static int mpc8_probe(AVProbeData *p)
77 uint8_t *bs = p->buf + 4;
78 uint8_t *bs_end = bs + p->buf_size;
83 if (AV_RL32(p->buf) != TAG_MPCK)
85 while (bs < bs_end + 3) {
86 int header_found = (bs[0] == 'S' && bs[1] == 'H');
87 if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
93 if (bs + size - 2 >= bs_end)
94 return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
96 if (size < 11 || size > 28)
98 if (!AV_RL32(bs)) //zero CRC is invalid
100 return AVPROBE_SCORE_MAX;
108 static inline int64_t gb_get_v(GetBitContext *gb)
112 while(get_bits1(gb) && bits < 64-7){
114 v |= get_bits(gb, 7);
118 v |= get_bits(gb, 7);
123 static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
127 *tag = avio_rl16(pb);
128 *size = ffio_read_varlen(pb);
129 *size -= avio_tell(pb) - pos;
132 static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
134 MPCContext *c = s->priv_data;
136 int64_t size, pos, ppos[2];
141 avio_seek(s->pb, off, SEEK_SET);
142 mpc8_get_chunk_header(s->pb, &tag, &size);
143 if(tag != TAG_SEEKTABLE){
144 av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
147 if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
149 avio_read(s->pb, buf, size);
150 init_get_bits(&gb, buf, size * 8);
151 size = gb_get_v(&gb);
152 if(size > UINT_MAX/4 || size > c->samples/1152){
153 av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
156 seekd = get_bits(&gb, 4);
157 for(i = 0; i < 2; i++){
158 pos = gb_get_v(&gb) + c->header_pos;
160 av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
162 for(; i < size; i++){
163 t = get_unary(&gb, 1, 33) << 12;
164 t += get_bits(&gb, 12);
167 pos = (t >> 1) + ppos[0]*2 - ppos[1];
168 av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
175 static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
177 AVIOContext *pb = s->pb;
182 pos = avio_tell(pb) + size;
183 off = ffio_read_varlen(pb);
184 mpc8_parse_seektable(s, chunk_pos + off);
185 avio_seek(pb, pos, SEEK_SET);
192 static int mpc8_read_header(AVFormatContext *s)
194 MPCContext *c = s->priv_data;
195 AVIOContext *pb = s->pb;
200 c->header_pos = avio_tell(pb);
201 if(avio_rl32(pb) != TAG_MPCK){
202 av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
206 while(!url_feof(pb)){
208 mpc8_get_chunk_header(pb, &tag, &size);
209 if(tag == TAG_STREAMHDR)
211 mpc8_handle_chunk(s, tag, pos, size);
213 if(tag != TAG_STREAMHDR){
214 av_log(s, AV_LOG_ERROR, "Stream header not found\n");
218 avio_skip(pb, 4); //CRC
219 c->ver = avio_r8(pb);
221 av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
224 c->samples = ffio_read_varlen(pb);
225 ffio_read_varlen(pb); //silence samples at the beginning
227 st = avformat_new_stream(s, NULL);
229 return AVERROR(ENOMEM);
230 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
231 st->codec->codec_id = CODEC_ID_MUSEPACK8;
232 st->codec->bits_per_coded_sample = 16;
234 st->codec->extradata_size = 2;
235 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
236 avio_read(pb, st->codec->extradata, st->codec->extradata_size);
238 st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
239 st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
240 avpriv_set_pts_info(st, 32, 1152 << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
241 st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
242 size -= avio_tell(pb) - pos;
247 int64_t pos = avio_tell(s->pb);
249 avio_seek(s->pb, pos, SEEK_SET);
255 static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
257 MPCContext *c = s->priv_data;
261 while(!url_feof(s->pb)){
262 pos = avio_tell(s->pb);
263 mpc8_get_chunk_header(s->pb, &tag, &size);
266 if(tag == TAG_AUDIOPACKET){
267 if(av_get_packet(s->pb, pkt, size) < 0)
268 return AVERROR(ENOMEM);
269 pkt->stream_index = 0;
273 if(tag == TAG_STREAMEND)
275 mpc8_handle_chunk(s, tag, pos, size);
280 static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
282 AVStream *st = s->streams[stream_index];
283 MPCContext *c = s->priv_data;
284 int index = av_index_search_timestamp(st, timestamp, flags);
286 if(index < 0) return -1;
287 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
289 c->frame = st->index_entries[index].timestamp;
294 AVInputFormat ff_mpc8_demuxer = {
296 .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
297 .priv_data_size = sizeof(MPCContext),
298 .read_probe = mpc8_probe,
299 .read_header = mpc8_read_header,
300 .read_packet = mpc8_read_packet,
301 .read_seek = mpc8_read_seek,